Body Fat Percentage Calculator
Estimate your body fat percentage using the U.S. Navy circumference method — one of the most practical and widely validated field methods. You only need a flexible tape measure. For a complete picture of your health numbers, also check your BMI and daily calorie needs.
Body Fat Categories
| Category | Men | Women |
|---|---|---|
| Essential fat | 2–5% | 10–13% |
| Athletic | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |
Source: American Council on Exercise (ACE)
How the Navy Method Works
The U.S. Navy circumference method estimates body fat from body measurements rather than underwater weighing or DEXA scanning. The formulas are:
Men: Body Fat % = 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76
Women: Body Fat % = 163.205 × log₁₀(waist + hips − neck) − 97.684 × log₁₀(height) − 78.387
All measurements are in inches for the Navy formula. Accuracy is typically within 3–4% compared to DEXA scanning, making it practical for personal tracking.
How to Measure Correctly
Getting accurate readings requires consistent technique:
- Neck: Measure just below the larynx (Adam's apple), keeping the tape slightly tilted downward toward the front.
- Waist (men): Measure at the navel. Keep your stomach relaxed — don't suck in.
- Waist (women): Measure at the narrowest point, usually just above the navel.
- Hips (women): Measure at the widest point across the buttocks.
Measure at the same time of day (morning is best) and take the average of two measurements to reduce error.
Limitations
The Navy method is accurate for most people but can overestimate body fat in very tall individuals and underestimate it in people who carry fat differently from the average. For the most accurate measurement, consider a DEXA scan at a sports medicine clinic. Once you have your body fat percentage, pair it with your TDEE Calculator results to set precise calorie and protein targets.
Frequently Asked Questions
What is a healthy body fat percentage? For general health, most guidelines target 15–20% for men and 20–27% for women. These ranges are associated with lower cardiovascular and metabolic disease risk.
How fast can body fat change? Realistically, losing 0.5–1% of body fat per month is sustainable. Faster loss usually involves muscle loss. Recheck your measurements every 4–6 weeks rather than weekly — daily fluctuations from water and food can be larger than monthly fat changes.
Is body fat percentage better than BMI? For body composition, yes. BMI cannot distinguish between muscle and fat, so muscular athletes often appear "overweight." Body fat percentage directly measures what you actually want to know. That said, BMI is faster and requires no tape measure, making it useful for a quick screen.
